12 April 2017

The final (maybe?) two articles from the Food and Brand Lab

It's been just over a week since Cornell University, and the Food and Brand Lab in particular, finally started to accept in public that there was something majorly wrong with the research output of that lab. I don't propose to go into that in much detail here; it's already been covered by Retraction Watch and by Andrew Gelman on his blog. As my quote in the Retraction Watch piece says, I'm glad that the many hours of hard, detailed, insanely boring work that my colleagues and I have put into this are starting to result in corrections to the scientific record.

The statement by Dr. Wansink contained a link to a list of articles for which he states that he has "reached out to the six journals involved to alert the editors to the situation". When I clicked on that list, I was surprised to see two articles that neither my colleagues nor I had looked at yet. I don't know whether Dr. Wansink decided to report these articles to the journals by himself, or perhaps someone else did some sleuthing and contacted him. In any case, I thought that for completeness (and, of course, to oblige Tim van der Zee to update his uberpost yet again) I would have a look at what might be causing a problem with these two articles.

First up, there is a considerable overlap in the text of these two articles. I estimate that 35–40% of the text from "Antecedents" had been recycled verbatim into "Bet", as shown in this image of the two articles side by side (I apologise for the small size of the page images from "Bet"):

The two articles present what appears to be the same study, from two different viewpoints (especially in the concluding sections, which as you can see above do not have any overlapping text) and with a somewhat different set of results reported. In "Antecedents", the theme is about education: broadly speaking, getting people to understand why the embark on phases of eating the same food, and the implications for dietary education. In "Bet", by contrast, the emphasis is placed on food marketers; the aim is to get them to understand how they can encourage people to consume more of their product. I suppose that, like the arms export policy of a country that sells arms to both sides in the same conflict, this could be viewed as hypocrisy or blissful neutrality.The Method and Results sections show some curious discrepancies. I assume the two articles must be describing the same study since the basic (212) and final (178) sample sizes are the same, and where the same item responses are reported in both articles, the numbers are generally identical, with one exception that I will mention below. Yet some details differ for no obvious reason. Thus, in "Antecedents", participants typically took 35 minutes to fill out a 19-page booklet, whereas in "Bet" then took 25 minutes to fill out an 11-page booklet. In "Antecedents", the reported split between the kinds of food that participants discussed eating was 41% sweet, 29% salty, 16% dairy, and 14% "other". In "Bet" the split was 52% sweet, 36% salty, and 12% "other". The Cronbach's alpha reported for coder agreement was .87 in "Antecedents" but .94 in "Bet".There are further inconsistencies in the main tables of results (Table 2 in "Antecedents", Table 1 in "Bet"). The principal measured variable changes from consumption intensity (i.e., the amount of the "eating bout" food that was consumed) to consumption frequency (the number of occasions on which the food was consumed), although the numbers remain the same. The ratings given in response to the item "I enjoyed the food" are 0.8 lower in both conditions in "Bet" compared to "Antecedents". On p. 14 of "Bet", the author reuses some text from "Antecedents" to describe the mean correlation between nutritiousness and consumption frequency, but inexplicably manages to copy the two correlations incorrectly from Table 2 and then calculate their mean incorrectly.Finally, the F statistics and associated p values on p. 175 of "Antecedents" and pp. 12–13 of "Bet" have incorrectly reported degrees of freedom (177 should be 176) and in several cases, the p value is not, as claimed in the article, below .05.

Is this interesting? Well, less than six months ago it would have been major news. But so, today so much has changed that I don't expect many people to want to read a story saying "Cornell professor blatantly recycled sole-authored empirical article", just as you can't get many people to click on "President of the United States says something really weird". Even so, I think this is important. It shows, as did James Heathers' post from a couple of weeks ago, that the same problems we've been finding in the output of the Cornell Food and Brand Lab go back more than 20 years, past the period when that lab was headquartered at UIUC (1997–2005), through its brief period at Penn (1995–1997), to Dr. Wansink's time at Dartmouth. When Tim gets round to updating his summary of our findings, we will be up to 44 articles and book chapters with problems, over 23 years. That's a fairly large problem for science, I think.
You can find annotated versions of the article discussed in this post here.